Question: How do I go about figuring how to "fill" around those shirt pieces that are too small for the block?
Hi mtiesen -
Making all the blocks the same size by filling in the smaller logos with fabric that coordinates with the border/sashing is a great idea. It sounds like your daughter wants all of the blocks to be similar, so this could work out pretty well. Doing this is simple.
Start by taking inventory of your blocks, and finding the size of the largest block, (say 15x15 inches). If you are lucky, many of them will already be close in size. You'd then have to apply a border around the smaller squares to bring them up to the larger size. A rectangular block would need two borders of fabric to make it square; a small square would need a full border to make it larger; etc. Add what you need to bring all of the logos up to the desired size. Then you can sew them all together in even rows, and then sew the rows together to make the quilt. Easy. Time consuming, but easy.
It looks like you have some smaller logos from fronts of shirts and numbers. You could sew four of them together to make one large block to match the size of the larger logos. If you have enough, it would be cute to put one of these "combo blocks" at each corner of the quilt (as you already have it laid out in the pic). I also see some very small logos - you could applique these onto some of the larger blocks that have a lot of open space.
This is going to be so neat when it is done! Ask more questions if I am not being clear. Looking forward to seeing the results!